Conventionally, as a fan clutch of this type, a fluid friction clutch for driving an engine cooling fan of a vehicle has been known (refer to Patent Literatures 1 and 2 and so forth). This fluid friction clutch has features as follows. The fluid friction clutch is structured to include a drive disk and a housing, an annular supply chamber (annular supply room) and a working chamber (activation room), a supply device for supplying shear fluid (oil) from the supply chamber to the working chamber and a reflow device for causing the shear fluid from the working chamber to reflow to the supply chamber, part of the supply chamber including a storage chamber (storage room) for the shear fluid and this storage chamber being separated from the working chamber by another portion of the supply chamber. The storage chamber is structured of an annular segment, the annular segment of the storage chamber is formed as a replenish container, the supply chamber includes at least one supply port and at least one reflow port (recycling port), and these supply port and reflow port form part of the supply device and the reflow device, respectively.
Also, a fan clutch capable of removably fixing a fan by a flange ring has been known, in which the fan clutch includes front-side and back-side housing components and the flange ring can be fixed to the housing by a coupling element. The fan clutch is configured so that when a fixing projection (tab) arranged on the flange ring is fixed to a fixing projection formed on the housing by the coupling element, the fixing projection (tab) arranged on the flange ring can fit from the front side or the back side of the fan clutch.